These “awakening” or thawing ice sheets will affect the world, from raising sea levels and threatening the existence of polar bears, to expanding maritime commerce and impacting national security, Abdalati noted.
One of the world's pre-eminent experts in the study of climate change, Abdalati provided evidence that the polar ice sheets are shrinking, drawing on data yielded by some 14 different scientific models used for predicting climate, to striking images of Greenland's and Antarctica's ice cover taken by NASA satellites.
The presentation was the latest installment in UD's William S. Carlson International Polar Year Events--a series of public programs named after UD's president from 1946-50 who conducted research in the Arctic. The lecture also was Webcast and simulcast to UD's island in the virtual world of Second Life.
Abdalati said he “fell in love with NASA” as a youngster, after watching the lunar landings. Today, he leads a group of scientists who monitor the planet's changing ice cover using satellites and other airborne instruments. He also is a veteran of nine field expeditions to the Greenland Ice Sheet.
“It's nature in its most austere form,” Abdalati said, showing a slide of a helicopter hovering along the edge of the Antarctic ice shelf towering taller than a football field above the waterline. “Does it matter that a place like this is changing?” he asked.
While Abdalati says the polar ice sheets “won't go tomorrow,” how much sea level rises in the future and how well we are prepared for it has huge social, political and economic implications for the world.
The impact of a one-meter (3.2 foot) rise in sea level in the world's oceans would amount to the inundation of 2.2 million square miles of coastline around the globe, the equivalent of one-quarter of the continental United States. It would affect 45 million people and cost a trillion dollars, Abdalati said.
Tools such as ice-penetrating radar and NASA's ICESat satellite have revealed that the Greenland Ice Sheet has a “weakened underbelly,” eroded by meltwater from thawing ice on the surface.
Since 1979, sea ice has been shrinking by about 8 percent per decade, Abdalati said. Every summer, sea ice thaws until it reaches a summer minimum. Then nature “presses a re-set button,” and the sea ice grows back in winter, he noted. However, the thick, old ice no longer exists in many places, leaving much thinner ice, more vulnerable to melting.
In 2007, scientists were stunned by the 23 percent reduction in sea ice that occurred from 2005-07. In 2007, a 76-year-old farmer from Minnesota navigated the largely ice-free Northwest Passage in a sailboat, he noted.
An ice-free Arctic Ocean has both negative and positive implications, Abdalati noted, providing the means for moving goods from Asia to Europe more quickly, and reducing the need to use the Suez Canal, not to mention increasing access to the Arctic's tremendous economic resources.
Besides the plight of the polar bears, whose numbers are diminishing, a warmer Arctic means melting permafrost.
As this frozen ground melts, it releases methane, a strong greenhouse gas. Melting permafrost already is costing Alaska some $35 million per year, where homes, highways and other infrastructure are affected by the sinking ground.
“Climatologically, we're in unfamiliar territory,” Abdalati noted. “The effectiveness of society's response depends on how big the changes are, how fast they come and how fast our ability will be to anticipate the changes.”
Earlier in the evening, Frederick “Fritz” Nelson, professor of geography and a member of the Nobel Prize-winning Intergovernmental Panel on Climate Change, introduced the audience to UD's Carlson IPY Events and the interesting connections the series has helped to forge, including contact with 93-year-old Ray Drakio, the last remaining survivor of the ill-fated Wilkins expedition of 1931 to explore the Arctic in a submarine. As fate would have it, Drakio happens to live in Newark, Del.
Tom Apple, dean of the College of Arts and Sciences, showcased the college's polar research and scholarship, highlighting the Bartol Research Institute and its work on the world's largest neutrino telescope at the South Pole; the Department of Geography's many projects such as the international Circumpolar Active Layer Monitoring (CALM) network of 168 observatories tracking permafrost and the Sea-ice Experiment: Dynamic Nature of the Arctic (SEDNA) project, a multi-institutional effort involving UD faculty in geography and computer and information sciences and a UD alumna to determine the mass balance of ice cover in the Arctic; study-abroad trips to Antarctica led by the Department of Communications; nonfiction works by faculty in the English Department, and the study and preservation of Inuit objects by the Center for Material Culture Studies.
Janis Tomlinson, director of University Museums, announced two exhibitions being planned for UD this fall in conjunction with the Carlson series, including historical images from the American Geographical Society Library at the University of Wisconsin-Milwaukee that recently were featured in “Photographs from the Ends of the Earth,” an exhibition curated by the Milwaukee Art Museum.The work of contemporary photographer Camille Seaman, including her majestic photos of icebergs, also will be presented.
For information on UD's polar research and outreach activities, visit [www.udel.edu/research/polar].
Photos by Jon Cox and Debbie Jeffers